1. Field of the Invention
This invention relates generally to video data processing, and more particularly, to a video input processor to pre-process different formats of video data including video format conversion, color space conversion, and multiple video input enhancement processing prior to video compression.
2. Description of the Related Art
As digital video applications become increasingly popular, there is a strong demand that video processing technologies be capable of dealing with a wide variety of video data or signals generated from different video sources.
For example, under CCIR (Consultative Committee for International Radio) 601, a NTSC television system outputs interlaced video signals at a resolution of 720×485 pixels with a frame rate of 30 fps (frame per second); a PAL system outputs interlaced video at a resolution of 720×576 pixels with a frame rate of 25 fps. Another common video format is the YUV 4:2:2 interfaced or progressive video, which is typically 8 bit video stream. If the video source is a CMOS sensor, the input video may be in a RGB Bayer format.
Conventional video processing technologies often lack the ability to process different video formats. For example, in the area of digital video compression, conventional techniques can only encode one specific format of video source in most of circumstances. To compress input video in different formats, conventional video compression techniques have to design different hardware or software modules dedicated for processing each different format. For example, if the video compression processor receives RGB Bayer input video, a specially designed hardware device needs to be developed to convert RGB Bayer data into RGB video; if the input is YUV interlaced video data, another specially designed hardware device has to be developed. Such specially designed hardware devices make processing different video data formats very expensive.
Further, conventional video processing technologies fail to provide optimal video encoding methods. For example, in the color space conversion field (i.e., converting RGB data into YCrCb or YUV component video), a conventional algorithm needs 12 clock cycles to complete the conversion process. It is desirable to design a new algorithm that requires fewer clock cycles to process and convert the video data.
In addition, a video input processor in conventional video processing systems does not have functions to enhance video or adapt to video compression needs, such as video filtering and video scaling.
Accordingly, what is needed is a video input processor capable of supporting multiple input video formats in a cost-effective manner and providing optimal algorithm for color space conversion. There is also a need for a video input processor that provides multiple pre-compression processing steps to enhance the video compression.